Modern textile machines usually function fully automatically, under the operational control of high-performance computers. Generally, the data required to control a textile machine is input into the computer of a central control unit associated with the textile machine, which also collects the event data from the various work stations. The work stations are typically identical spinning stations. In addition, work station-independent data is linked to work station-specific data and then control commands are transmitted to the work stations from the central control unit. The work stations in turn may each include decentralized control units with so-called work station computers, which substantially automatically control the timing and sequence of operational steps performed at the work stations, also referred to herein as a course of work. The data required for this can be transmitted to the work stations from the central control unit or may be entered decentrally at each work station into a memory associated with the work station control unit. In the latter case, only the data ascertained at a central station or point of the textile machine needs to be transmitted to the control units of the work stations. In a spinning machine, such data may include the rotary speeds of the draw-off rollers and winding shaft.
For example, the rotary speed, usually presented as rpm, of the draw-off shaft is measured centrally in a spinning machine and is linked in the central control unit with the ongoing data from the various work stations to determine the wound-up yarn length, which is then associated with the various work stations so as to initiate a bobbin change when the desired length is reached.
German Patent Disclosure DE 39 28 381 A1 discloses how the data exchange between the textile machine work station control units and the textile machine central control unit can be effected and what infrastructure is appropriate for the purpose. In the known textile machine, each work station computer associated with the work station control unit is connected via a data bus to the central control unit computer associated with the textile machine. In other words, the bus system of this kind of multi-station textile machine must be designed so that it can simultaneously transmit substantial amounts of data without interference. In an open-end spinning machine, for instance, up to 300 spinning stations can be connected to the computer of the central control unit over a single shared bus.
To enable correct association of the data with the various work stations, each work station is assigned an address, which is made up of a code. This code must be added upon each data transmission, so that the data can be addressed to the correct work station or associated with the work station that had transmitted the data. The addressing and decoding require computer capacity and time in addition to programming effort and maintenance.